In today's In Ear Monitors (IEMs) and similar devices for Personal Use (Personal Monitors), very often more than one receiver is used to obtain the required performance in terms of frequency range extension and maximum sound pressure capability. One example of such a multiple receiver or speaker IEMs is disclosed in US Published Patent Application 2006/0133636, titled “Sound Tube Tuned Multi-Driver Earpiece.” In such receivers/speakers, it is required to connect the separate sound outlets or spouts of each receiver to respective appropriately dimensioned sound tubes or sound conducting members in an acoustically sealed manner. The 3300 series receiver manufactured and sold by Sonion Nederland B.V comprises two back-to-back mounted moving armature receivers with separate sound ports emitting respective sound signals into a common spout. Both of these solutions put requirements to the space required by and the acoustical properties of this acoustical coupling.